Displacement Maps look pixelated in EEVEE
This is a known limitation as of Blender 2.80. Displacement maps aren’t truly supported. The displacement shaders will only affect the normals, not the actual vertex positions. Aka, it’s a bump map. And all bump maps in Eevee are currently limited to 2x2 pixels blocks, see https://docs.blender.org/manual/en/dev/render/eevee/limitations.html#materials